FDA-filed SPL labeling · retrieved through openFDA

Bezlotoxumab Injection

Bezlotoxumab injection (Zinplava) is a targeted antibody therapy used to help prevent Clostridioides difficile (C. diff) infection from coming back in adults and children 1 year and older who are already being treated with antibiotics.

Brand name Zinplava
Rx Form 1 Route Intravenous
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

At a glance
Linked label effectiveNov 12, 2024
AvailabilityRx
Earliest approval/marketing year 2016
FDA-listed product records 4
Boxed warningNone found in compared labels
How we combine label and product data →
No current FDA shortage listed · checked Sep 15, 2026
Bezlotoxumab Injection at a glance The quick version — the full detail is in the Patient Information Guide below.
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HelloPharmacist Editorial Team Bottom Line
Zinplava is a one-time IV infusion given alongside antibiotics to lower the risk of C. diff infection returning in high-risk patients. It is not an antibiotic and cannot treat C. diff on its own. People with a history of congestive heart failure should discuss the risks carefully with their doctor before receiving it.

📖 Bezlotoxumab Injection: Patient Information Guide

A plain-language walkthrough of Bezlotoxumab Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.

🎯What it's used for

Bezlotoxumab injection (brand: Zinplava) is approved for one specific purpose: reducing the chance that a Clostridioides difficile (C. diff) gut infection will return.

  • Zinplava is used to reduce recurrence of Clostridioides difficile infection (CDI) in adults and in children 1 year of age and older who are currently receiving antibiotic treatment for CDI and are considered at high risk for the infection coming back.
  • Zinplava must always be used together with antibiotic treatment — it is not a standalone treatment for C. diff and is not itself an antibiotic.
  • Zinplava is not approved for children younger than 1 year of age.
⚙️How it works

Zinplava (bezlotoxumab) is a human monoclonal antibody — a precisely engineered protein that targets a specific substance in the body. It works by binding directly to C. difficile toxin B, one of the harmful toxins the bacteria release that damages the gut lining and drives infection. By latching onto toxin B and neutralizing it, Zinplava helps block the toxin's damaging effects and reduce the likelihood of C. diff coming back.

Because Zinplava targets toxin B directly rather than going through the liver's enzyme systems, no metabolic drug interactions are expected with other medications.

💊How it's taken

Zinplava is given as a single intravenous (IV) infusion — a drip into a vein — over 60 minutes. It is dosed based on body weight and given just once during a course of antibiotic treatment for C. diff. You do not take it at home; a healthcare provider prepares and administers it in a clinical setting.

  • It must be diluted before infusion — it is never given as a direct push or bolus injection.
  • No other drugs should run through the same IV line at the same time.
  • The safety of giving it more than once has not been studied.
🤒Side effects — in detail

Most people tolerate Zinplava well. The most common side effects seen in clinical trials include:

  • Nausea
  • Fever (pyrexia)
  • Headache
  • Fatigue (on the day of or day after infusion)
  • Dizziness
  • Shortness of breath (dyspnea)
  • High blood pressure during infusion

Infusion-related reactions are generally mild to moderate and typically resolve within 24 hours. However, serious heart failure events were reported — particularly in patients who already had congestive heart failure — so tell your care team immediately if you notice worsening breathing, swelling, or other new heart-related symptoms after your infusion.

⚠️Warnings & precautions
  • Heart failure risk: In clinical trials, patients with a history of congestive heart failure (CHF) who received Zinplava had a meaningfully higher rate of serious heart failure events and deaths compared to those who did not receive it. If you have CHF, your doctor must carefully weigh the benefits against this risk before giving Zinplava.
  • Infusion-related reactions: About 10% of patients experienced a reaction on the day of or day after infusion — including nausea, headache, fever, dizziness, or shortness of breath. These are usually mild and short-lived.
  • Heart rhythm: One patient in trials developed a serious irregular heartbeat (ventricular tachyarrhythmia) during infusion, requiring the infusion to be stopped. You will be monitored during administration.
  • Not a C. diff treatment on its own: Zinplava does not treat the active infection — always use it alongside the prescribed antibiotic.
🔀What it interacts with

Zinplava is broken down by the body's natural protein-recycling process (catabolism) rather than through liver enzymes, so drug-drug interactions involving metabolism are not expected. No specific drug interactions are identified in the prescribing information.

  • No other medications should be infused through the same IV line at the same time as Zinplava — keep lines separate during administration.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

📋Before taking it
  • History of congestive heart failure (CHF): Tell your doctor — Zinplava is associated with higher rates of serious heart failure events in people with this condition and should only be used if the benefit clearly outweighs the risk.
  • Pregnancy: There are no adequate studies in pregnant women. Discuss the risks and benefits with your doctor.
  • Breastfeeding: It is unknown whether Zinplava passes into breast milk. Talk to your doctor about the best approach for you and your baby.
  • Children under 1 year: Safety and effectiveness have not been established in this age group — Zinplava is not approved for infants under 1 year old.
  • Older adults (65+): No dose adjustment is needed. Safety and effectiveness were similar to younger adults in clinical trials.
🚑If you take too much

There is no clinical experience with Zinplava overdose. If too much is given, the patient should be closely monitored for any signs or symptoms of side effects, and supportive care should be provided as needed. Contact a healthcare provider or poison control center immediately if an overdose is suspected.

🔬Pharmacokinetics — how your body processes it

After a single weight-based IV infusion, Zinplava reaches its peak level in the bloodstream during the infusion itself. It stays in the body for an extended period — its elimination half-life (the time it takes for half the drug to leave the body) is approximately 19 days.

The body clears Zinplava through catabolism — the same natural process used to break down other proteins — rather than through liver enzymes. People who weigh more clear the drug a little faster, but the weight-based dosing approach accounts for this. Factors like gender, race, ethnicity, and other medical conditions do not meaningfully change how the body handles Zinplava.

📦How to store it

Store in a refrigerator, 2ºC to 8ºC (36ºF to 46ºF) in original carton to protect from light. Do Not Freeze.

📄 Written from Bezlotoxumab Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →

🩺 Pharmacist Counseling Corner

Quick, plain-English answers to the questions patients ask most about Bezlotoxumab Injection — the kind of thing our pharmacy team would talk through with you at the counter.

What exactly is Zinplava doing — is it an antibiotic that kills the C. diff bacteria?
No, Zinplava is not an antibiotic and it doesn't kill C. diff bacteria at all. It's actually a specially engineered antibody — a protein — that targets one of the toxins C. diff produces called toxin B. By grabbing onto that toxin and neutralizing it, Zinplava helps prevent C. diff from coming back after you've already been treated with antibiotics. Think of it as a 'shield' against recurrence, not a treatment for the active infection.
I'm already taking an antibiotic for C. diff. Why do I need Zinplava on top of that?
Great question. C. diff has a frustrating tendency to come back, especially in people considered high risk. The antibiotic you're taking tackles the active infection, but Zinplava is given alongside it specifically to lower the chance the infection returns once the antibiotics are done. The two work together — Zinplava isn't a replacement for your antibiotic, so it's important to keep taking both as directed.
Will I need to come in for multiple infusions, or is this a one-time thing?
It's a single, one-time infusion. You'll come in, and a healthcare professional will give it to you through an IV drip over about 60 minutes. That's it — just the one dose. The safety of giving it more than once hasn't been studied, so repeat dosing isn't done.
What side effects should I expect, and when should I call someone?
Most people do very well. The most common side effects are nausea, fever, and headache, and some people notice mild dizziness, fatigue, or shortness of breath on the day of or the day after the infusion. These usually pass within 24 hours. The one thing to watch for closely — especially if you have a history of heart failure — is any worsening shortness of breath, swelling, or other new heart symptoms after your infusion. If that happens, contact your doctor right away.
I have congestive heart failure. Is Zinplava safe for me?
This is really important to discuss with your doctor. In clinical trials, people who already had congestive heart failure had higher rates of serious heart failure events — and more deaths — after receiving Zinplava compared to those who got a placebo. That doesn't mean you absolutely can't have it, but your doctor needs to weigh whether the benefit of preventing C. diff recurrence outweighs that risk for you specifically. Make sure your care team knows your full heart history before your infusion.
I'm pregnant or breastfeeding — is Zinplava okay to use?
There haven't been adequate studies of Zinplava in pregnant women, and it's not known whether it passes into breast milk. That means your doctor will need to carefully weigh the benefit of preventing a serious C. diff recurrence against any potential risk to you or your baby. Be open with your care team about your situation so they can make the best call for both of you.
Is Bezlotoxumab Injection available over the counter?
Bezlotoxumab Injection is dispensed by prescription according to its FDA labeling, so it isn't sold over the counter. Your prescriber and pharmacist will determine if it's appropriate for you.
When was Bezlotoxumab Injection first available?
Bezlotoxumab Injection has been available in the United States since at least 2016, based on FDA approval history (Drugs@FDA) and product marketing records.
Who makes Bezlotoxumab Injection?
Bezlotoxumab Injection is supplied by 2 manufacturers listed in the FDA NDC Directory, including Merck Sharp & Dohme LLC, MSD Ireland (Carlow).

💬 Answers drafted from Bezlotoxumab Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →

🧰 Keep exploring

💊 How Bezlotoxumab Injection comes

Bezlotoxumab Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Injection

By injection · Into a vein
Brands Zinplava
How this form is used
What it may be used for
  • Zinplava is used to reduce the recurrence of Clostridioides difficile infection (CDI) in adults and pediatric patients 1 year of age and older who are receiving antibiotic treatment for CDI and are at high risk for CDI coming back
Important instructions
  • Zinplava must be diluted before administration and is given as a single intravenous infusion over 60 minutes
  • Zinplava is administered during — not instead of — antibiotic treatment for C. diff
  • Zinplava must not be given as an intravenous push or bolus, and no other drugs should be infused through the same line at the same time
  • Zinplava is dosed based on body weight and is given only once; repeat administration has not been studied
Available strengths 1 strength
4 FDA-listed product records

📊 Bezlotoxumab Injection across the U.S. market

How Bezlotoxumab Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

1
Dose forms
2
Manufacturers
1
Brand names
4
FDA-listed product records
2016
First marketed
Merck Sharp & Dohme LLC75%
MSD Ireland (Carlow)25%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

🔍 Compare Bezlotoxumab Injection products

A representative set of FDA-listed product records for Bezlotoxumab Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Strength Route Manufacturer / Labeler Category Details
💊Injection
25 mg/mL Intravenous Merck Sharp & Dohme LLC × 3 listings BLA View NDC →
25 mg/mL MSD Ireland (Carlow) DRUG FOR FURTHER PROCESSING View NDC →

Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Bezlotoxumab Injection NDCs →

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Bezlotoxumab Injection RxCUI 1855048 1 dose form · 1 strength
  1. Dose form (SCDF) Injection RxCUI 1855051 In current FDA listings
    Clinical drug / strength (SCD) 40 ML bezlotoxumab 25 MG/ML RxCUI 1855052

Look up RxCUI 1855048 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

🏷️ Sold under these brand names

Zinplava

🏭 Manufacturers & labelers

Merck Sharp & Dohme LLC 3 MSD Ireland (Carlow) 1

RxNorm drug class

Bezlotoxumab Injection belongs to the Antibacterial monoclonal antibodies class.

Drug family (ATC) Antibacterial monoclonal antibodies

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

🔬 Where this comes from

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Nov 12, 2024
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Bezlotoxumab Injection.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
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Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Bezlotoxumab Injection after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
1
NDC products indexed
4
Distinct labelers/manufacturers represented
2
Linked representative label
Merck Sharp & Dohme LLC
Linked label effective
Nov 12, 2024
Composite sections available
22
Linked SPL Set ID
8f479bfe-2bfa-4cc5-9aee-1357364480b0
Linked SPL Document ID
12338d29-efb0-4943-b5f5-826350e9ec46
Open the linked representative label on DailyMed ↗

How we combine label and product data

HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.

Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Merck Sharp & Dohme LLC is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.

This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.